Without heterogeneity in ideology-preferences and opinions over political actions-there would be little need for the institutions studied by political economists.1 However, the sources of ideology have received scant attention: since Marx, political economists have largely viewed ideology as driven by wealth or income-despite the fact that these variables explain little of the variation in ideology ( This paper proposes a complementary theory in which differences in ideology are also due to imperfect information processing. This theory predicts that overconfidence in one's own beliefs leads to ideological extremeness, increased voter 1 Without heterogeneity, institutions will still be useful for coordination (Weingast 1997). Traditionally, opinions have not been considered part of ideology; however, recent work has provided compelling arguments that ideology should include some beliefs (McMurray 2013a, b).

We conduct an experiment in which subjects face the same questions repeated multiple times, with repetitions of two types: (1) following the literature, the repetitions are distant from each other; (2) in a novel treatment, the repetitions are in a row, and subjects are told that the questions will be repeated. We find that a large majority of subjects exhibit stochastic choice in both cases. We discuss the implications for models of stochastic choice.

Abstraet A phenomenon of certainty effbet is well known as a typical paradox in expected utility theory and is often observed in the laboratory gambling to test the axiomatic system of utility theory, A necessary and suffUcient condition that the certainty effect is observed is demonstrated by .means of a generalized utility function and some properties ef individual's behavior derived from the condition are discussed.

When choosing between options, such as food items presented in plain view, people tend to choose the option they spend longer looking at. The prevailing interpretation is that visual attention increases value. However, in previous studies, 'value' was coupled to a behavioural goal, since subjects had to choose the item they preferred. This makes it impossible to discern if visual attention has an effect on value, or, instead, if attention modulates the information most relevant for the goal of the decision-maker. Here we present the results of two independent studies—a perceptual and a value-based task—that allow us to decouple value from goal-relevant information using specific task-framing. Combining psychophysics with computational modelling, we show that, contrary to the current interpretation, attention does not boost value, but instead it modulates goal-relevant information. This work provides a novel and more general mechanism by which attention interacts with choice.

This paper develops axiomatically a revealed preference theory of reference-dependent choice behavior. Instead of taking the reference for an agent as exogenously given in the description of a choice problem, we suitably relax the Weak Axiom of Revealed Preference to obtain, endogenously, the existence of reference alternatives as well as the structure of choice behavior conditional on those alternatives. We show how this model captures some well-known choice patterns such as the attraction effect. (JEL D11, D81)